from math import pi, sqrt
def cairo_draw( ctx, w, h ):
	ctx.scale (w/1.0, h/1.0)

	pat = cairo.LinearGradient (0.0, 0.0, 0.0, 1.0)
	pat.add_color_stop_rgba (1, 0, 0, 0, 1)
	pat.add_color_stop_rgba (0, 1, 1, 1, 1)

	ctx.rectangle (0,0,1,1)
	ctx.set_source (pat)
	ctx.fill ()

	pat = cairo.RadialGradient (0.45, 0.4, 0.1, 0.4,  0.4, 0.5)
	pat.add_color_stop_rgba (0, 1, 1, 1, 1)
	pat.add_color_stop_rgba (1, 0, 0, 0, 1)

	ctx.set_source (pat)
	ctx.arc (0.5, 0.5, 0.3, 0, 2 * pi)
	ctx.fill ()
